This invention generally relates to automated clutch control in a vehicle driveline. More particularly, this invention relates to providing a driver with an indication of an open clutch condition in such a vehicle driveline.
Vehicle transmissions and clutches are well known. In many vehicles where there are a relatively high number of available gear ratios in the transmission, relatively complex or challenging manual shifting sequences must be accomplished by a driver to successfully complete a shift between gears. For example, engine speed for synchronizing speeds between rotating shafts in the driveline must be controlled within certain tolerances to successfully complete a shift. For inexperienced drivers, such shifting may be challenging, difficult or impossible under some circumstances.
A variety of improvements over recent years have simplified the task of shifting such transmissions. Various functions have been automated to simplify the shifting process. For example, engine speed synchronization techniques automatically control engine speed to achieve the necessary speed synchronization so that a successful shift can be made. A variety of such techniques are known.
Other improvements include automated clutch actuators that remove the requirement for a driver to manually operate a clutch pedal to open or close a clutch. A variety of such clutch operators and control strategies are known.
One particular arrangement includes allowing the driver to select a desired starting gear and then automatically closing the clutch responsive to a launch command from the driver. Pressing the accelerator pedal may be one example launch command. One shortcoming of such a system is that it presents the possibility for the driver to leave the transmission in gear with the clutch open for an extended period of time. There are various reasons why such a condition should be prevented.
This invention provides a control strategy for avoiding leaving the clutch open under undesirable conditions, such as when the transmission is in gear.